- ページ 12
録音機器 dbx 166のPDF クイック・スタート・マニュアルをオンラインで閲覧またはダウンロードできます。dbx 166 18 ページ。 Professional dynamics processor
dbx 166 にも： クイックマニュアル (17 ページ)
ページを印刷する
Normally, the
control
is
set
to
just
under the peak
clipping level of
the
equipment
downstream.
This
way,
clipping
will
be
softer
and
controlled within
the
166.
The
LED
should
light
occasionally,
on
p^ks
only?
if
the
LED
lights
often, of
course,
reduce the
compression
threshold and/or increase the
ratio,
to allow
less
peak
signal level
at the
output.
SIDECHAIN APPLICATIONS
In
all
the following
situations,
it's
the Sidechaln
Monitor
function that
will
save you
time and
trouble, letting
you
adjust
the preceding
processor(s)
and
instantly
confirm
that
things
are
(or
aren't)
going the
way
you
want them
to.
General
hints
It's
possible to
separate certain vocals
and
Instruments
from
a
mix
by
making
the
compressicm
frequency-sensitive.
With an
equalizer inserted into the Sidechaln input
(but
not
in
the audio
path),
the
EQ
settings
do
not
shift
the
timbre
or
equalize the audio
signal;
they
merely
alter
the threshold
of
the
compressor
as
a
function
of
frequency.
In
such an
arrangement,
frequencies that are boosted
on
the equalizer
will
be
sup-
pressed
in
the audio
signal.
The
converse
may
also
be
used, of course: dipping the equal-
izer
on a
particular
band prevents any sound with dominant energy
in
the
affected
regis-
ter
from
compressing so
much,
because the 166
will
detect
less
need
for
compression.
For example,
if
you want
to
suppress an overly loud bass
drum,
boost the equal-
izer's
response
below about
150 Hz.
This
will
make
the
compressor reduce
gain
whenever
energy
in
this
region
is
detected. Furthermore,
raising
the
threshold
will
cause
this
to
happen
only
on
very loud
kicks.
To
put
it
generally,
a
relatively
high threshold setting
can
prevent
most
sounds
from
being affected while
solo
and very
loud
sounds
within that
frequency range are
held back. (Of course,
when
compression does
occur, the entire
program
level
is
affected.)
Depending
again
on
the threshold
setting,
frequencies outside
that
range
will
not
cause compression.
During the recording
of
cymbals and
toms, a compressor with an
EQ
in
the
side-
chain path
can
help prevent tape saturation.
The
equalizer
can be
adjusted
for
a
boost
peaking
at
about
5
kHz,
causing the
cymbal
to
be compressed on a very
loud crash
and
stopping saturation of the
tape
at
higher frequencies,
where
there's
less
headroom.
How-
ever, gentle tapping
with a
stick or
cymbal
brushing
will
not
be
held back.
And
the
tom-
tom
likewise,
being a lower -frequency instrument
and
better-tolerated by the tape, has
less
need
for
compression.
EQ
in
the sidechaln
circuit
can
make
the
compressor
not as
readily
triggered
by a
loud
tom-tom
beat
as
by an
equally loud
cymbal
crash.
De-essing
In
the
absence
of
a
de-esser, small
amounts
of
high-frequency
(6-10
kHz)
boost
In
the sidechaln path frequently
will
help
in
the processing
of
vocals that
may
have been
brightly
equalized beforehand or that
suffer
from prominent
sibilance
("ess"
sounds).
Speaker protection
If
a
single
compressor
is
to
be
used with a
multi-way
sp>eaker
system
(after
EQ,
before the
crossover),
you
are
faced with the problem
of
keeping the
entire
system
level
down
below
the point
of
destruction of the
most
sensitive
component.
If
midranges
are
frequently blown,
for
example, the whole system must be
run at
a lower
SPL
or addi-
tional
mids must be added.
By
the
insertion of
an
equalizer
in
the sidechaln
of
the
166,
It
can
be
made
sensitive to
the frequencies the
midranges
handle,
permitting the
entire
PA
system
to
be
run at higher
average
levels
and dropped back
only
when
damaging
signals
are
present.
-
10
-